Which animal has a low risk of heat exhaustion?

Fish that live in cold waters have a low risk of heat exhaustion because they are ectothermic, meaning their body temperature is regulated by the surrounding water. Cold-water fish thrive in stable, cooler environments, which helps prevent overheating. Unlike warm-blooded animals that generate heat internally and have to manage their body temperature in fluctuating environmental conditions, these fish are adapted to their specific aquatic habitats that maintain a lower temperature, thus minimizing the risk of heat stress. Their physiological adaptations allow them to function optimally in colder water without the concerns of heat exhaustion that affect mammals, reptiles, or birds, which must actively manage their body temperatures in response to their environments.